1. Field of the Invention
The present invention relates to an inkjet head used in an inkjet recording apparatus and to a method of manufacturing the inkjet head.
2. Description of the Related Art
Hitherto, employed as an energy generating element for an inkjet recording apparatus are an energy generating element using an electro-mechanical transducer such as a piezo element or the like, an energy generating element heated by an electromagnetic wave such as laser irradiated thereto for ejecting droplets of ink by the action of heat, an energy generating element for heating liquid by an electro-thermal transducer having a heat generating resistance member, and the like.
In the inkjet recording apparatus, there is known an inkjet head for performing print by ejecting a plurality of different types of liquids through two rows of an orifice array so as to cope with a requirement for high image quality and high speed printing. There is also known an inkjet head which utilizes only one of two rows of orifice arrays when photo ink is not necessary in a graph and the like.
In FIG. 7, reference numeral 1 denotes a top plate on which a liquid flow path groove liquid chamber and orifice arrays are disposed, reference numeral 2 denotes a wiring substrate for electrically connecting a heater board having a resistance heating element mounted thereon to a carriage, reference numeral 3 denotes an elastic body for pressing and fixing the heater board against and to the top plate 1, reference numeral 24 denotes a color orifice array drilled through the top plate 1 for ejecting color inks (Y, M, C), respectively, and reference numeral 25 denotes an elastic member for improving the intimate contact between the heater board and the top plate 1.
In the above inkjet head, the top plate of a photo head is constructed similarly to that of a color head and a head assembling device can be commonly used, which permits the inkjet head to be made without the provision of a new device.
In the color head of the above conventional example, the heater board is pressed against the top plate only on one side thereof through the elastic body, the disposition of the orifice array, when an inkjet head is completed, may be different from the disposition thereof when the top plate is completed.
Further, when the heater board is coupled with the top plate and when the elastic member is inserted, an unused side ink flow path is moved, from which arises a problem that the intimate contact of a used side heater board with a liquid flow path groove is made bad and characters are irregularly printed.
Accordingly, it is an object of the present invention to provide an inkjet head, in which a dummy board having the same shape as that of a heater board is disposed in an intimate contact state and a rib is disposed in the vicinity of an unused side ink feed path to increase strength, so as to improve an intimate contact property, to eliminate irregular print and to reproduce the disposition of orifice arrays on a top plate as a single isolated member even at the time an inkjet head is completed, and to provide a method of manufacturing the inkjet head.
To solve the above problem, the present invention provides an inkjet head arranged as shown in the following items (1) and (2) and a method of manufacturing the inkjet head.
(1) In an inkjet head acting as a liquid ejecting head for carrying out a print operation by ejecting liquids onto a medium to be recorded, the inkjet head including two rows of orifice arrays, which are disposed approximately parallel with each other and a group of supply ports for feeding the liquids to the orifice arrays, the orifice arrays and the supply ports being arranged integrally, and only one of the two rows of the orifice arrays being used, the inkjet head is characterized in that a dummy heater board having the same shape as that of a heater board is caused to come into intimate contact with an unused side liquid chamber.
(2) In an inkjet head acting as a liquid ejecting head for carrying out a print operation by ejecting liquids onto a medium to be recorded, the inkjet head including two rows of orifice arrays, which are disposed approximately parallel with each other and a group of supply ports for feeding the liquids to the orifice arrays, the orifice arrays and the supply ports being arranged integrally, and only one of the two rows of the orifice arrays being used, the inkjet head is characterized in that ribs are disposed in the vicinity of an unused side ink path so as to increase strength.
(3) A method of manufacturing of an inkjet head in which two boards are jointed to each other through an elastic member at positions which are symmetrical with respect to a top plate member including a plurality of orifices for ejecting inks and a supply port for feeding inks to the array of the plurality of orifices and a flow path is formed so as to communicate with the orifices, the inkjet head using only one of the two boards for ejecting inks includes the steps of pressing and fixing the board used for ejecting inks against and to the top plate by an elastic member; and pressing and fixing a board, which is not used to eject inks, against and to the top plate to which the board used to eject inks has been fixed.
Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.